The American singer Glen Campbell did not care for musical boundaries. He probably enjoyed hearing The Meters, doyens of New Orleans funk, covering Wichita Lineman, as much as he enjoyed performing a slow, country-tinged version of Foo Fighters’ rock anthem, Times Like These.

Because Campbell, who has died at the age of 81, had a particular role in American popular music. Without doubt, he was a mainstream artist – but he eschewed middle-of-the-road status by driving right across it.

The lynchpin of his fame was the straddling of country and pop, notably on his trio of hits with songwriter Jimmy Webb in the late 1960s – By The Time I Get To Phoenix; Galveston, and Wichita Lineman – and, later on, Rhinestone Cowboy. Indeed, his abundant skill as an interpreter led in 1967 (the year of the “Summer of Love”) to Grammy Awards for vocal performance in both the country and contemporary categories, for Gentle On My Mind and By The Time I Get To Phoenix respectively.

But his appeal as a vocalist belied a far broader hinterland and skill set. Growing up in small town Arkansas, his key influences included the fiery jazz guitarist Django Reinhardt. Campbell was a prodigiously talented and versatile guitarist and after working through country bands and Western Swing – a combination of country and jazz – he moved to Los Angeles in 1960 to become a sought-after session player.

There he was a member of the “Wrecking Crew”, a group of musicians who dominated the session scene in the 1960s and early 1970s. Campbell’s work as a guitarist graced the work of Elvis Presley, Frank Sinatra, Dean Martin and The Monkees. He played on The Beach Boys’ seminal Pet Sounds album, and stood in with falsetto vocals for a run-down Brian Wilson when the band toured.

Cross country

This blend of rural grit and West Coast production sophistication informed his own hits, allowing for an appeal that traversed country and pop audiences. And although he credited the success of his collaboration with Jimmy Webb to the fact that they had grown up near one another (Webb was from Oklahoma), it also resided in their ability to convey country sentiments beyond that genre.

Campbell’s legacy lies not just in the breadth of his work but in combining different versions of “America” into his songs. Places such as Galveston, in Texas, had not been part of the mythical language of American pop and rock. But he gave them an emotional resonance which added a universal dimension to his music, threading a sense of country traditionalism through a glossier pop product.

He eschewed the “bad boy” public persona of other country stars including Johnny Cash and Merle Haggard in his music. But his personal life was stormy, and riven at times with alcohol and drug dependency. While Cash and others wore their demons on the sleeve as part of their musical identity, Campbell’s version of authenticity resided not in rebel credentials but in a dedication to musical craft, finely honed songs and impeccable delivery – the rhinestones on the cowboy.

It was a professional veneer, alongside his easy-going manner and square-jawed look, which also saw him break into movies, including a role alongside John Wayne in True Grit, and host his own television show.

This meant there were contractions. Despite charting with Buffy Saint-Marie’s anti-war song Universal Soldier, he decried anyone unwilling to fight for their country as “not a real man”. Likewise, Webb and Campbell differed in their view of their hit Galveston, in which the protagonist dreams of his Texas home from the battlefield. Campbell gave it a patriotic sheen, which Webb, its composer, shied away from.

Despite telling Billboard magazine in 1970 that he wasn’t interested in getting “mixed up in politics”, Campbell’s conservative leanings included public statements in support of Ronald Reagan and an appearance at the Republican president’s inauguration. But it rarely seemed a priority for Campbell. The music and entertainment came first.

True grit

It was this flexibility – and ultimately his disregard for genre boundaries – that stoked his lasting appeal among subsequent generations of musicians as well as his peers. His 2011 album Ghost on the Canvas featured contributions from the likes of Chris Isaak and Smashing Pumpkins’ Billy Corgan, and songs by alternative rock writers like The Replacements’ Paul Westerberg and Guided by Voices’ Robert Pollard.

Prioritising the musicality of the song, whatever its origins, allowed Campbell to project a version of America that bridged rural and urban, merging rather than crossing over. In the process, he sidestepped some of the potentially divisive or troubling aspects of his routine as an entertainer to pull his various influences into an aesthetic that drew from staid patriotism through the Great American Songbook and could speak to the cosmopolitan .

The term “middle-of-the-road” can carry pejorative connotations. But there’s scope for individuality and distinctiveness there, too, which Campbell leveraged his consummate musicianship towards. For him, it was less a compromise than a clear path.